Device for personal safety on scaffolds

ABSTRACT

The present invention relates to a device for personal safety on such scaffolds as consist of scaffold uprights ( 5, 6 ) and lying scaffold elements ( 64 - 73 ) coupled between the uprights. The safety device consists of two safety uprights ( 18, 19 ) and a guard rail ( 24 ) extending between the safety uprights. The safety uprights have coupling devices ( 20 - 23 ) for releasable coupling-together with the scaffold. The coupling devices interact with an upwardly facing portion of the scaffold. By means of the device, the safety uprights and the accompanying guard rail can be moved successively between different vertical positions according to safety requirements.

TECHNICAL FIELD

The present invention relates to a device for personal safety onscaffolds according to the precharacterizing clause of Patent claim 1below.

BACKGROUND ART

In assembled scaffolds, there are means for personal protection againstfalling in the form of fixed guard rails which are coupled between thescaffold uprights in a scaffold. At the same time, these formstabilizing parts of the scaffold and hold the scaffold uprights in anerect position.

When scaffolds are being erected and dismantled, scaffold erectors oftenwork on the parts of the scaffold which do not have guard rails. Inorder to provide protection against falling, use is made of safetyharnesses with lifelines which, however, limit the freedom of movementof the person. Safe anchoring points must be selected and moved as thework progresses.

Attempts have been made to arrange movable guard rails for erecting anddismantling operations (see for example GB 1 528 220), but these haveproved difficult to handle for scaffold erectors.

DISCLOSURE OF INVENTION

The object of the present invention is to produce a device in whichextra guard rails can be handled and moved with great safety.

The said object is achieved by means of the device according to thepresent invention, the characteristics of which emerge from Patent claim1 below.

LIST OF FIGURES

The invention will be described in greater detail below by means of afew illustrative embodiments with reference to accompanying drawings inwhich

FIG. 1 shows an embodiment of the safety device according to theinvention in a perspective view at an angle from the front, mounted in alower safety position on a scaffold;

FIG. 2 shows the safety device in a position during movement between anupper and a lower safety position;

FIG. 3 shows the safety device in an upper safety position;

FIGS. 4, 5 and 6 show different views of a safety upright forming partof the safety device according to the invention;

FIGS. 7 and 8 show partial side views of a safety upright with anactuating device and a coupling device which can be adjusted by thelatter in on the one hand locking position and on the other handreleasing position, and

FIG. 9 shows the safety upright from above.

PREFERRED EMBODIMENT

FIGS. 1-3 show the construction in principle of a safety device 1 forpersonal safety on scaffolds 2. The safety device 1 is shown by somewhatheavier lines, while the scaffold is shown by somewhat lighter lines inorder that the safety device emerges more clearly. The scaffoldcomprises a number of scaffold uprights, in the example shown accordingto FIG. 1 four uprights 3, 4, 5, 6, which in pairs support between themat least one working platform 7 which can be positioned at differentheights in order to make work possible at different heights along, forexample, the facade of a house construction. The platform or platformsis or are supported between the uprights arranged in pairs by virtue of,for example, having hooks which are coupled to transverse, lying,suitably horizontal scaffold elements 66-73 which extend between theuprights 3 and 4 and, respectively, 5 and 6.

The scaffold also includes fixed scaffold rails 64, 65 which areaccordingly arranged so that each scaffold rail is arranged between thetwo outermost uprights 3 and 6 in order to afford protection in theoutward direction, for example at a suitable height above a workingplatform 7. These fixed rails can be fastened directly to the scaffolduprights 3, 6 or to the transverse scaffold elements.

Erection of the scaffold proceeds from the bottom, as the uprights 3-6are to rest with their lower ends 14, 15 against a surface, for examplethe ground or a floor. Erection is started by lower sections of at leasttwo uprights, for example 3 and 4, being held in an erect position,standing on the surface, after which two connecting elements, a scaffoldrail and if appropriate the working platform 7 and diagonal elements(not shown) as well are mounted, at least the lower sections of the fouruprights then being held erect. As erection continues above the workingplatform 7, heights are reached which involve risks of accident. Forexample, the scaffold may be intended to have such a height that eachupright consists of several sections which are joined to one another,after which scaffold rails and working platforms located above are to bemounted.

In order to safeguard personnel when the scaffold is being erected anddismantled, a safety device 1 according to the invention has thereforebeen produced, which is adapted to be moved upwardly or downwardly asthe scaffold is being erected and, respectively, dismantled. To thisend, the safety device 1 (see FIG. 1) consists of at least one, in theexample two safety uprights 18, 19 which are each provided with one ormore coupling devices 20, 21, 22, 23 for releasable coupling-togetherwith the scaffold. In the example shown, each safety upright 18, 19 isprovided with two coupling devices arranged at a distance from oneanother for a coupling-together which ensures that the safety uprightsextend essentially parallel to the scaffold uprights. The safetyuprights 18, 19 support between them at least one guard rail 24 which,in the example shown, consists of an upper rail element 25 and a lowerrail element 26. The two rail elements 25, 26 are connected at theirends 27, 28, 29, 30 to the safety uprights 18, 19; to be precise, in theexample they are connected to the safety uprights in an articulatedmanner, suitably adjacent to the upper end of the safety uprights sothat the upper rail element is located close to the respective upperends 31, 32, while the lower rail element 26 is located a little waybelow at a distance which is adapted for the protection functionconcerned.

For each of the safety uprights 18, 19, the safety device has anactuating device 33, 34 with at least at one end 35, 36 of each safetyupright, in the example shown both ends 35-38, actuating means 39, 40,41, 42 for adjusting the coupling devices 20-23 between releasingposition and coupling position. In the coupling position, the couplingdevices are adapted on the one hand to secure the safety uprights 18, 19in their parallel position and on the other hand to maintain theselected vertical position of the safety uprights, that is to say tolock them relative to movements in the axial direction of the uprights.To this end, the safety uprights receive, through the coupling devices,support against bearing surfaces in the scaffold, in the example shownthe lying scaffold elements 66-73, that is to say horizontal tubes, inthe example one end side element 10, 12 for each coupling device 20-23.

FIG. 1 also shows that the end of each rail element 25, 26 is connectedin an articulated manner to its safety upright 18, 19 by means of afastening arrangement in the form of an articulation arrangement 43which makes possible relative articulated movement of the rail elementabout an axis 44 which extends essentially at right angles relative toon the one hand the longitudinal axis of its safety upright and on theother hand the longitudinal axis of the rail element. The rail elements25, 26 are therefore supported at their ends by the safety uprights 18,19 via the articulation arrangement. The articulation arrangements canbe connected firmly to the uprights but can alternatively bedisplaceable between different vertical positions along the uprights andlockable on these in the selected vertical position.

FIGS. 4, 5 and 6 show a safety upright 18 separately from differentdirections with the two coupling devices 20, 21, which are thereforelocated at a distance axially from the guard rail 24, and with theassociated actuating device 33, with its actuating means 39, 41, one ateach end 35, 37 of the safety upright. One of the coupling devices 20 isshown on larger scale in FIGS. 7-9 and consists in the example shown ofa gripping hook 45 with a downwardly open gripping space 46 which isdesigned and dimensioned to receive a lying scaffold element 72 in thescaffold, so that the safety upright 18 rests on the lying scaffoldelement by means of the coupling device 20. A cross section of thescaffold element is indicated by broken lines. The gripping space 46 isprovided with a gripping opening 47, facing in the direction away fromthe guard rail 24, that is to say downwards. The coupling device 20 hasa locking means 48 which is adjustable between a locking position forthe coupling device, which is shown in FIG. 7, and a releasing positionwhich is shown in FIG. 8. In the example shown, the locking meansconsists of a locking bolt which is anchored movably in the grippinghook 45 and can be displaced into and out of the gripping opening 47. Inlocking position, the effective downwardly facing gripping opening 47shrinks to a dimension smaller than the diameter of the scaffold element10. The locking bolt 48 is advantageously designed with a lockingsurface which, together with the concave inner surface 50 of thegripping hook, is adapted to afford good contact with and stable supportagainst the outer surface of the scaffold element which is cylindricalin the example shown. In this connection, the locking bolt can be pushedforward, for example by means of a diagrammatically illustrated springmechanism 51, so that play-free contact is obtained between the supportsurfaces. In the releasing position according to FIG. 8, it is possibleto pull the gripping hooks 45 of the coupling devices 20 away from thescaffold element so that the gripping hooks can be taken out of couplingposition and removed from the scaffold element 10 in order to be movedto a new safety position or for dismantling. It is important that stablesupport is obtained in the releasing position as well in order to holdthe safety device in a selected vertical position.

FIGS. 7-9 also show the actuating device 33 of the coupling devices.Accordingly, this includes the actuating means 39-42 which are locatedat the ends of each safety upright 18, 19. In the example shown, eachactuating means consists of a handle which is mounted rotatably in theupright and, in the example shown, arranged in a rotationally fixedmanner at the upper and the lower end of a turning bar 52 which ismounted rotatably coaxially in each safety upright and extends all theway through the safety upright or at least as far as the couplingdevices. Arranged at each coupling device is a movement-transmittinglink mechanism 55 which is adapted to convert the actuating movement ofeach actuating means 39, 41 into an adjusting movement of the lockingmeans 48 in the associated coupling device 20 between the lockingposition according to FIG. 7 and the releasing position according toFIG. 8. In the example shown, the movement-transmitting link armmechanism consists of a link arm 56 and a push rod 57. The link arm 56is connected to the turning bar 52 in a rotationally fixed manner, andthe push rod 57 is at its one end connected in an articulated manner tothe link arm and at its other end connected to the locking means so as,by the rotary movement, to bring about a longitudinal displacementmovement of the locking means counter to the action of the springmechanism 51, for example a helical spring (compression spring) which isrestrained between the locking means and a fixed surface in the couplingdevice and is threaded onto the push rod and tends to hold the lockingmeans 48 in locking position.

By means of a slot in the articulation point, the push rod 57 and thusthe locking bolt 48 can perform a pure longitudinal displacementmovement. Alternatively, the locking means can be pivotable.

The coupling devices are suitably arranged firmly on the safetyuprights, in the example shown by virtue of the gripping hook 45 mergingwith a short arm 58 with a hole in one of its ends. The hole isdimensioned and shaped so that the safety upright 18 will pass throughit. Firm connection can take place by means of a welded joint, a screwedjoint or the like.

In the example shown, the guard rail 24 in the safety device iscontinuously extendable, for example by virtue of each rail element 25,26 being telescopically extendable and consisting of, for example, anouter tube 59 and an inner tube 60 which can be inserted telescopicallyinto the outer tube. More than two tubes can be present in order toobtain a greater adjustment range. The length-adjustability means thatone and the same safety device can be used for different lengths ofworking platform 7, that is to say different distances between thescaffold uprights 18, 19, and makes possible the successive movement ofone safety upright 18, 19 at a time in the safety device as the scaffoldis being erected or dismantled.

The use of the safety device according to the invention during erectionof a scaffold will now be described below.

As mentioned previously, the erection of the scaffold proceeds from thebottom, with the erection of a number of scaffold uprights and themounting initially of a bracing scaffold element, which can be mountedat a low height, on the whole by personnel on the ground. In theexample, fixed scaffold rails 64, 65 in the form of lying, longitudinalscaffold elements are mounted between the two front scaffold uprights 3,6, after the transverse, lying scaffold elements 66-73 which are coupledbetween the front scaffold uprights 3, 6 on one side and the rearscaffold uprights 4, 5 on the other side. The first working platform 7can then be positioned at a suitable height by its hooks 74, 75, whichgrip around the transverse scaffold elements 66, 70. Depending on theheight of the final scaffold, use is made of a number of sections foreach scaffold upright, starting with lower sections and then graduallyjoining on additional sections as the scaffold is erected. Joining-on isadvantageously carried out so that all sections of the scaffold uprightsare arranged along one and the same longitudinal axis.

Before personnel step onto the working platform 7, the safety device ismounted so that the associated guard rail 24 will be located at asuitable safety height above the working platform (see FIG. 1). Mountingis suitably carried out by two people, it being possible for the safetydevice to be assembled on the ground. For transport purposes, the safetyuprights 18, 19 are suitably disconnected from the guard rail 24 at thearticulation arrangement 43. In the storage and transport state, thesafety device according to the example shown thus forms essentially anumber of parallel tubes. The mounted safety device 1 is positioned withits two safety uprights 18, 19 on the inside of the scaffold uprights 3,6 adjacent to which the safety uprights are to be arranged, in theexample the outer uprights. This is carried out at such a height that,as mentioned above, the guard rail 24 affords effective protectionduring subsequent scaffold erection. Furthermore, the coupling devices20, 21, 22, 23 are adjusted to releasing position, after which theircoupling hooks are each made to grip around a respective lying scaffoldelement 66, 67, 70, 71 so as to be supported by the latter by resting onthe associated scaffold element. In this connection, the mounted safetyupright 19 is held in a stable support position with a fixed verticalposition. Then, the nearest accessible actuating means, for example thelower actuating means 41, 42, is activated for adjustment to lockingposition. Activation takes place under the action of the springmechanism 51, which ensures that the locking position is maintainedduring use of the safety device. By virtue of the rail elements 25, 26of the guard rail 24 being connected in an articulated manner at theirends to the safety uprights and moreover being extendable, erection doesnot have to take place entirely synchronously on the two sides, but cantake place individually, the rail elements being, on account of theiradjustable length, adaptable to the distance concerned between thescaffold uprights. The coupling devices are advantageously secured onthe associated scaffold uprights in such a way that the structure isalso secured against movements in the lateral direction. This isachieved either by high friction in the support surfaces or by thelocking means 48 not only locking but clamping or firmly gripping thescaffold element in the recess 50.

In its first safety position according to FIG. 1, the safety device 1can be mounted either from ground level or from another safe workingposition, for example from what is known as a skylift, by virtue ofactuating means 39-42 being arranged at both ends of the safety uprights18, 19. With the safety device in the position shown, personnel can verysafely remain on the working platform 7 in order to continue theerection of the scaffold. For example, further sections of scaffolduprights can be added, after which permanent scaffold rails can bemounted inside the guard rail 24 and a working platform (not shown)located above can be mounted.

Before the scaffold is erected further upwards, the safety device 1according to the invention is moved further upwards. In this connection,one safety upright 19 is first freed by adjustment (in the examplerotation) of one of the actuating means 40, 42 at the ends of the safetyupright, suitably the lower end. A scaffold erector can in thisconnection activate the actuating means 42 for release, after which helifts the safety upright 19 upwards along the scaffold upright 6 (seeFIG. 2). This is possible by virtue of the rail elements 25, 26 beingarticulated at their fastening points and telescopically extendable, ascan be seen from FIG. 2. When the raised end of the guard rail 24 hasreached the desired height, the safety upright 19 is coupled to thescaffold close to the scaffold upright 6. The two coupling devices 22,23 are in this connection each made to grip around a respective lyingscaffold element, in this case two transverse elements 68, 69 which havethe same mutual interspace as the gripping hooks on the safety upright.Then, one of the actuating means 40, 42, suitably the lower actuatingmeans 42, is activated (in the example released) for changing thecoupling devices 22, 23 over to coupled or locked position. In thisconnection, the safety upright 19 obtains vertical support against anelement in the scaffold. Support in the lateral direction is obtained byfriction in the gripping hooks and support against the scaffold upright.Special stop means on the lying scaffold elements are also possible. Theother side of the safety device 1 can then be moved up by the leftsafety upright 18 being released by means of, for example, the actuatingmeans 41, after which, for example, a person standing to the left on theworking platform 7 can lift the safety upright 18 up to the desiredposition, suitably with the guard rail 24 essentially horizontal (seeFIG. 3), after which the coupling devices 20, 21 are adjusted tocoupling position. It is conceivable for a single scaffold erector to dothis because one safety upright is handled at a time.

The safety device 1 is then in the safety position according to FIG. 3,and scaffold erectors can then very safely erect the scaffold further ifso required. In this connection, further scaffold uprights can be addedon top of the four scaffold uprights shown, and a permanent scaffoldrail can be mounted inside the guard rail of the safety device.

When the scaffold is erected, the safety device can in principle remainin its top position and either afford supplementary protection or ifappropriate replace the top guard rail.

When the scaffold is dismantled, the procedure is in principle the sameas described above, but in reverse order, as the various elements of thescaffold are taken down starting from the top.

The invention is not limited to illustrative embodiments described aboveand shown in the drawings but can be varied within the scope of thepatent claims below. For example, it may in some cases be sufficient tohave one coupling device on each safety upright. If this is given agreater extent in the vertical direction, a torsion-resistant couplingcan still be obtained. In principle, it is conceivable for the fasteningdevices for the guard rail 24 to be fixed, that is to say notarticulated, and for the rail elements to be unextendable and adapted intheir length to the distance between the scaffold uprights 3, 6. Forexample, the safety device can permanently have the appearance thesafety device in FIGS. 1 and 3 has.

In the case of a safety device with a guard rail without articulations,it is particularly suitable if such an embodiment is intended for theend sides, that is to say the short sides, of the scaffold and can stilladvantageously be coupled to the lying, transverse scaffold elements onthe end sides. In this connection, it is conceivable for the safetydevice to be provided with a single safety upright, the guard railprojecting laterally from the safety upright and therefore beingconnected to the safety upright without articulation. Such end sidesafety devices can moreover be combined with articulated safety devicesaccording to the example shown, it then being possible therefore for theguard rail for the long sides to be fastened to a safety upright sharedwith a short side. It is also conceivable for only one of the couplingdevices to be lockable, in the case of an articulated construction onelock in each safety upright, in the case of a rigid construction it isin principle sufficient for one safety upright to be locked.Furthermore, the coupling devices can be coupled to other parts of thescaffold, for example one or two at a time of the longitudinal lying(horizontal) scaffold elements.

Alternatively, the safety uprights can be coupled to the coupling meansof the scaffold uprights, which may be a cup running around, or abracket or plate with a hole for hooking in gripping elements. Acombination of gripping hooks for support against lying elements andhooks for hooking firmly to scaffold uprights is also conceivable. It isthen sufficient for one type of hooks to be lockable. Instead of anactuating handle and turning bar, another actuating device can beselected, for example a pull/push rod or wire which is pulled in theaxial direction, the actuating means then being a pull/push means. Acommon feature of the various coupling devices is that they rest on anupwardly facing portion of the scaffold in order that the safety uprightor safety uprights will be secured safely to the scaffold in couplingposition and released for movement of the safety device.

1. Device for personal safety on such scaffolds as consist of scaffolduprights (3, 4, 5, 6) and lying scaffold elements (64-73) adapted to becoupled between the uprights, the safety device consisting of at leastone safety upright (18, 19) and at least one guard rail (24) extendingfrom the safety uprights, the guard rail being fastened to theassociated safety uprights and the said safety device having at leastone coupling device (20-23) for releasable coupling-together with thescaffold, as a result of which the said safety uprights and theaccompanying guard rail can successively be moved between differentvertical positions according to safety requirements, the safety device(1) comprising at least one actuating device (33, 34) with actuatingmeans (39-42) for adjusting the said coupling device (20-23) between areleasing position and a coupling position for coupling safety uprightstogether with parts of the scaffold in different vertical positions, thesaid actuating means (39-42) being arranged at at least one end of thesaid safety uprights (18, 19) and being adapted to be adjusted betweenreleasing position and coupling position and, viaactuating-movement-transmitting means (52, 55, 57) extending along theassociated safety uprights, to adjust the coupling device (20-23)between releasing position and coupling position, characterized in thatthe coupling devices (20-23) are adapted to support the safety device(1) in both releasing position and coupling position by resting on anupwardly facing portion of the scaffold.
 2. Device according to Patentclaim 1, characterized in that each coupling device (20-23) has agripping hook (45), the hook opening (47) of which, viewed in thelongitudinal direction of the safety upright (18, 19), faces away fromthe associated guard rail (24), that is to say downwards in the safetyposition, in order to grip around a portion of the scaffold.
 3. Deviceaccording to Patent claim 1, characterized in that each coupling device(20-23) is held in position in both the vertical direction and thelateral direction on the scaffold.
 4. Device according to Patent claim1, characterized in that the actuating means (39-42) are arranged atboth ends (35-38) of the said safety uprights (18, 19).
 5. Deviceaccording to Patent claim 1, characterized in that the saidactuating-movement-transmitting means (52, 55, 57) comprise an actuatingbar (52) which extends inside the associated safety upright (18, 19). 6.Device according to Patent claim 5, characterized in that the actuatingbar (52) extends through the entire length of the safety upright (18,19), and in that the actuating means are arranged on both ends of eachactuating rod.
 7. Device according to Patent claim 5, characterized inthat the actuating bar (52) is mounted rotatably in the safety upright(18, 19).
 8. Device according to Patent claim 7, characterized in thatthe said actuating means (39-42) consist of a handle which is mountedrotatably relative to the safety upright (18, 19) at its end and isarranged in a rotationally fixed manner on the respective end of theactuating bar (52).
 9. Device according to Patent claim 8, characterizedin that the turning bar (52) extends from the handle at each end to alink mechanism (55, 57) which is located at each coupling device (20-23)and is adapted to convert the actuating movement of the actuating barinto an adjusting movement of a locking means (48) in the associatedcoupling device between the releasing position and the couplingposition.
 10. Device according to Patent claim 1, characterized in thatthe number of coupling devices (20-23) is at least two on each safetyupright (18, 19).